Telephone-transmitter.



No. 673,350. Patented Apr. 30, I90l.

- C, E. YOCOM. v

TELEPHUI IE IBANSIMTTEB.

(Application am Feb. 4, 1901.;

(No Model.)

UNITED STATES PATENT OFFICE.

CHARLTON E. YOOOM, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO JAMES G. MOFADYEAN, OF PITTSBURG, PENNSYLVANIA.

TELEPHONE-TRA NSM-ITTER.

SPECIFICATION forming part of Letters Patent N 0. 673,350, dated April 30, 1901.

Application filed Pehuary 4, 1901. Serial No. 45,921. (N model.)

skilled in the art towhich it appertains to I make and use the same. i i

This invention relates to telephone-trans- .mitters of that class of instruments in which the to-and-fro motions of the transmittingdiaphragm are caused to vary the resistance, of a button, of carbon, placed in the local circuit, and more particularly to transmitters in which the sound-waves are simultaneously directed against the exposed surfaces of two diaphragms.

The objects of the invention are to produce a transmitter of this character which shall be adapted to attain more satisfactory results than are ordinarily obtained in the transmission and reproduction of articulate speech, especially at long distances, and to make a simple and inexpensive instrument the parts of which may be easily assembled and adjusted in position for use or taken apart when desired. y

The invention will first be hereinafter more particularly described with reference to the accompanying drawings, which are to be taken as a part of this specification, and then indicated in the claims at the endof the description.

In the drawings, which illustrate only one form of embodiment of my invention, Figure 1 represents a sectional side elevation of a telephone-transmitter constructed in accordance with my invention. Fig. 2 represents a horizontal section on the line 2 2 of Fig. 1, and Figs. 3, 4:, and 5 are details of parts of the transmitter in perspective.

The letter A in the drawings may denote a casing or housing in which the transmitting device proper 0r resistance-varying mechan:

ism and cooperative parts are inclosed, so as to provide a passage-way at each side of the transmitting device communicating with a mouthpiece A, common to both passages and secured to said casing in any desired manner. Said transmitting device in the form shown is indicated by the letter B and consists of two outer diaphragms B B and an intermediate diaphragm G, separated by insulating supports or annuli D D, each of the outer diaphragms having secured thereto or associated therewith a carbon element 1), which may be in the form of an ordinary carbon button, and a surrounding electrode-retainer b, which is preferably composed of textile fabric extending from the inner face of the outer diaphragm and having frayed edges, which bear slightly upon the opposing surface of the intermediate diaph ragm,the textile material of which said retainer is composed being dense enough to prevent the powdered carbon or othergranular materialtof the electrode confined therein from being displaced by creeping betweenthe fibers thereof and at the same time sufficiently elastic or yielding to permit the diaphragms to vibrate freely V for exerting pressure upon the electrode or resistance-varying medium. Within the circular space between the carbon element or lar material, such as powdered carbon or carbon-dust. The intermediate diaphragm G. is preferably composed of sheet-carbon and is designed to be connected with one pole of the battery or the primary wire of aninductioncoil of the usual local circuit, the other side of the circuit being electrically connected with both of the outer diaphragms B B, as indicated in Fig. 2 of the drawings, in which the circuit may be traced by the wires, having the branches 0, to the two diaphragms B B, thence through the carbon elements or buttons b and the granular electrodes to the carbon or intermediate diaphragm C, and thence to the wire 0 completing the circuit through the instrument. For conveniently holding together the diaphragms, insulatingrings, and interposed electrodes and retaining means, assembled as above indicated and shown in the drawings, a resilient or other thereon' so as to confine said parts in fixed positions relatively toeach other byth'e resiliency of the said band, causing it to close upon the assembled parts, or by securing the ends thereof together, as may be found most desirable in practice. Such retaining-band may be dispensed with, however, and the several diaphragms and cooperative parts forming the transmitter proper may be secured together in any desired manner. By the described construction I produce a transmitting device in which the sound-waves are adapted .to act simultaneously upon the exposed surfaces of the two outer diaphragms, between which and the inner diaphragm there is 'an unoccupied space at each side of the latter .surrounding'each electrode,-and the amount of electrode-surface is doubled as compared with transmitters of the usual construction,

in which a granular electrode is employed between two diaphragms, one in electrical connection with one side andthe other with the other side of the circuit, and I thus secure a highly sensitive and efiic'ient instrument, which is especially adapted for transmittin g messages to long distances as well as desirable for local use. Moreover, when in a slate of rest the resistance in. the electric circ'uit is comparativelyvery high,'which tends circuit.

to. prolong the life of the battery inthe local This transmitting device in any suitable caseor housing havingpassage-ways for dividing the sound-waves in .such 'manneras to causethe sameftoa'ct simnltaneo'usly"against the exposed faces of both outer diaphragms. A convenient form is illustrated in the drawings, in which a sim.-.

ple band ais passed around the transmitting device and provided with lugs a on the in-. terior thereof to prevent lateral movementof said device, the said band having sufficient width to leave aspace or passage-way a at each side of the transmitter in com munica! 'tion'with a mouthpiece A', common to both passages. Said'mouthpiece mayhave a screw-' threaded portion to be screwed into a coup ling-piece a fitting around an opening in the retaining-band a, and the open ends of the latter may be closed by side pieces a, having annular flangescf thereon, which extend into the'drum or cylinder formed by the retaining-band and are secured thereto bysuitable-bolts and nuts or other fastenings.

Having thus fully described myinvention, what I claim as new, and desire to secure by Letters Patent of the United States, is

. 1. A multiple-diaphragm telephone-transmitter, comprising three diaphragms slightly separated each from the other by insulating supports or annuli; the two outer diaphragms each having a carbon element about its cen-v ter, a granular electrode interposed between each of said carbon elements and said intermediate diaphragm, and electrical connections for completing the usual local circuit 1 through the instrument byconnecting both may be inclosed.

outer diaphragms with 'o'neside and the intermediate-diaphragm with the other side of the circuit, substantially as described. I

2. A multiple-diaphragm telephone-transmitter, comprising two outer diaphragms and an intermediate diaphragm separated each in part of sheet-carbon, an insulating support or annulus at each side of said carbon diaphragm separating it from the outer diaphragms, and a granular electrode interposed between each of said carbon elements and said intermediate diaphragm, together with means for holding said parts together.

4. A'multiple-diaphragm telephone=transmitter, comprising two outerdiaphragm's each having a carbon element at its center, an intermediate diaphragm composed whollyor in' part of sheet-carbon, an insulating support or annulusat each side of said carbon diaphragm separating it'from the outer diaphragms, and a granular electrodeinterposed between each of said carbon elements and said intermediate diaphragm, together with .means for'holding said parrstogether, and

means. for. electricallyconnecting-both outer diaphragms with one side and the intermediate diaphragm with the other side" of the usual local circuit. I g

5. A multiple-diaphragm telephone-transmitter, com prising two outer diaphragms each having. associated therewith a centrally-disposed carbon element, an intermediate diaphragm composed wholly or in part of sheetcarbon," an insulating support or annulus interposed between each outer diaphragm and the intermediate diaphragm, a granular electrode at each side of said intermediate diaphragm in contact with one of said centrallydisposed carbon elements, and textile material projecting from the outer diaphragms and surrounding the'electrode for retaining the same about the center of the intermediate diaphragm.

6. In a multiple diaphragm telephonetransmitter, two outer diaphragms, each carrying a centrally-disposed carbon element, an intermediate diaphragm, an insulating-annw .lus separating each outer diaphragm from said intermediate diaphragm a'granular electrode interposed between each of said carbon elements and said intermediate diaphragm,

IIO

and means forholding said parts together, in

combination with a casing inclosing said assembled parts and provided with a passageway for sound-waves at each side thereof, and a mouthpiece communicating with said passage-ways.

7. In a multiple diaphragm telephonetransmitter, the combination of outer diaph ragins each having a carbon element associated therewith, an inner diaphragm, insulating-su pports separating the inner and outer diaphragms, a granular electrode interposed between said carbon elements and said intermediate diaphragm, and a retainer composed of textile material surrounding the granular electrode and confining the same in place about the center of the inner diaphragm.

8. A multiple-diaphragm telephone-transmitter, comprising several diaphragms each having a carbon element associated therewith, an insulating-support separating the outer and inner diaphragms, a granular electrode interposed between the carbon elements on the opposing surfaces of all the diaphragms, and non-conducting flexible material surrounding the electrodes and confining The same about the centers of the diaphragms.

9. A multiple-diaphragm telephone-transmitter, comprising several diaphragms each having a carbon element associated therewith, an insulating-support separating the outer and inner diaphragms, a granular electrode interposed between the carbon elements on the opposing surfaces of all the diaphragms, and non-conducting flexible material surrounding the electrodes and confining the same about the centers of the diaphragms, in combination with an inclosing case having side passages and a mouthpiece common to both passages, substantially as described.

10. A m ultiple-diaphragm transmittercomprising two outer diaphragms each having a centrally-disposed carbon element associated therewith, an intermediate carbon diaphragm, an insulating and separating annulus arranged between each of said outer diaphragms and said carbon diaphragm, textile material extending inward from said outer diaphragms in the form of annuli, and granular electrodes within said annuli in contact with opposing surfaces of said carbon elements and intermediate diaphragm, substantially as described.

11. In a telephone-transmitter, the combination with a diaphragm secured between ining case having a mouthpiece, in combination with the transmitting device properarranged within the case so as to provide a passageway at each side thereof communicating with said mouthpiece, said transmitting device consisting of several diaphragms, the outer ones forming theinner walls of said passages, an intermediate diaphragm and support therefor separating the latter from the outer diaphragms,a cen orally-disposed carbon element associated with each of said outer diaphragms, a granular electrode and means for supporting the same between each of said carbon elements and said intermediate diaphragm, and circuit-wires for completing the electric circuit through said electrodes and intermediate diaphragm.

13. The combination in a telephone-transmitter, of a casing having a passage at each side thereof and a mouthpiece communicating therewith, two diaphragms forming the inner walls of said passages each having a carbon element about its center, an intermediate diaphragm, an insulating-support interposed between each of said outer diaphragms and said intermediate diaphragm, a granular electrode interposed between each of said carbon elements and said intermediate diaphragm, and circuit-wires for completing the usual local circuit leading from said carbon diaphragm to one side of the circuit and from both of said outer diaphragms to the other side of the circuit, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

CHARLTON E. YOC OM.

Witnesses:

BLAIR SHOEMAKER, S. G. HOPKINS. 

